Overall, the energy-saving of doors and windows is mainly reflected in the improvement of their insulation performance. The energy-saving of doors and windows in cold areas in the north focuses on insulation, while in hot summer and warm winter areas in the south, insulation is emphasized, while in hot summer and cold winter areas, both insulation and insulation should be considered. Improving the thermal insulation performance of doors and windows can be considered from the following aspects.

1.Strengthen the thermal insulation performance of doors and windows

This focuses on existing buildings in southern China, such as hot summer and cold winter areas and hot summer and warm winter areas. The thermal insulation performance of doors and windows mainly refers to the ability of doors and windows to block solar radiation heat from entering the room during summer. The main factors affecting the thermal insulation performance of doors and windows include the thermal performance of door and window materials, inlay materials (usually referring to glass), and photophysical properties. The smaller the thermal conductivity of the door and window frame material, the smaller the conductivity of the door and window. For windows, using various special thermal reflective glass or thermal reflective films has a good effect, especially selecting reflective materials with strong infrared reflection ability in sunlight, such as low radiation glass, is ideal. But when selecting these materials, it is necessary to consider the lighting of the window and not improve the insulation performance by losing the transparency of the window, otherwise, its energy-saving effect will be counterproductive.

2. Strengthen shading measures inside and outside windows

On the premise of meeting the design requirements inside the building, adding external sunshades, and sunshades, and appropriately increasing the length of the south-facing balcony can all have a specific shading effect. A thermal reflective fabric curtain coated with a metal film is installed on the inner side of the window, with a decorative effect on the front, forming a poorly flowing air layer of about 50mm between the glass and the curtain. This can achieve good thermal reflection and insulation effect, but due to poor direct lighting, it should be made into a movable type. In addition, installing blinds with a particular thermal reflection effect on the inner side of the window can also achieve a specific insulation effect.

3. Improve the insulation performance of doors and windows

Improving the insulation performance of building exterior doors and windows mainly refers to increasing the thermal resistance of doors and windows. Due to the small thermal resistance of single-layer glass windows, the temperature difference between the inner and outer surfaces is only 0.4 ℃, resulting in poor insulation performance of single-layer windows. The use of double or multi-layer glass windows, or hollow glass, utilizing the high thermal resistance of the air interlayer, can significantly improve the thermal insulation performance of the window. In addition, selecting door and window frame materials with low thermal conductivity, such as plastic and heat-treated metal frame materials, can improve the insulation performance of external doors and windows. Generally speaking, the improvement of this performance also enhances the insulation performance.

4. Improve the airtightness of doors and windows

Improving the airtightness of doors and windows can reduce the energy consumption generated by this heat exchange. At present, the airtightness of exterior doors and windows in buildings is poor, and the airtightness should be improved from the production, installation, and installation of sealing materials. When designing, the determination of this indicator can be considered based on the hygiene air exchange rate of 1.5 times/h, which does not necessarily require doors and windows to be absolutely airtight. For buildings in the northern region, enhancing the airtightness of doors and windows has a significant impact on reducing winter heating energy consumption.